Add Windows ARM32 (thumbv7a-pc-windows-msvc/thumbv7a-uwp-windows-msvc) support

build.rs

@@ -83,6 +83,7 @@ const RING_SRCS: &[(&[&str], &str)] = &[
  (&[ARM], "crypto/curve25519/asm/x25519-asm-arm.S"),
  (&[ARM], "crypto/fipsmodule/modes/asm/ghash-armv4.pl"),
  (&[ARM], "crypto/poly1305/poly1305_arm.c"),
+ (&[ARM], "crypto/poly1305/poly1305.c"), // For Windows ARM32 only
  (&[ARM], "crypto/poly1305/poly1305_arm_asm.S"),
  (&[ARM], "crypto/fipsmodule/sha/asm/sha256-armv4.pl"),
  (&[ARM], "crypto/fipsmodule/sha/asm/sha512-armv4.pl"),
@@ -223,6 +224,13 @@ const ASM_TARGETS: &[AsmTarget] = &[
  asm_extension: "S",
  preassemble: false,
  },
+ AsmTarget {
+ oss: &[WINDOWS],
+ arch: "arm",
+ perlasm_format: "win32",
+ asm_extension: "S",
+ preassemble: false,
+ },
 ];
 
 struct AsmTarget {
@@ -432,8 +440,17 @@ fn build_c_code(
 
  generate_prefix_symbols_asm_headers(out_dir, ring_core_prefix).unwrap();
 
+ let is_win_arm32 = target.arch == ARM && target.os == WINDOWS;
  let (asm_srcs, obj_srcs) = if let Some(asm_target) = asm_target {
- let perlasm_src_dsts = perlasm_src_dsts(asm_dir, asm_target);
+ let perlasm_src_dsts = perlasm_src_dsts(asm_dir, asm_target)
+ .into_iter()
+ .filter(|(src, _)| {
+ if !is_win_arm32 {
+ return true;
+ }
+ !src.to_string_lossy().contains("armx")
+ })
+ .collect::<Vec<_>>();
 
  if !use_pregenerated {
  perlasm(&perlasm_src_dsts[..], asm_target);
@@ -472,6 +489,18 @@ fn build_c_code(
  }
  true
  })
+ .filter(|p| {
+ let file_name = p.file_name().unwrap().to_string_lossy();
+ if file_name.contains("poly1305.c") {
+ return is_win_arm32;
+ }
+ if !is_win_arm32 {
+ return true;
+ }
+ !["poly1305"]
+ .into_iter()
+ .any(|keyword| file_name.contains(keyword))
+ })
  .collect::<Vec<_>>();
 
  let test_srcs = RING_TEST_SRCS.iter().map(PathBuf::from).collect::<Vec<_>>();
@@ -576,7 +605,10 @@ fn obj_path(out_dir: &Path, src: &Path) -> PathBuf {
 
 fn configure_cc(c: &mut cc::Build, target: &Target, include_dir: &Path) {
  // FIXME: On Windows AArch64 we currently must use Clang to compile C code
- if target.os == WINDOWS && target.arch == AARCH64 && !c.get_compiler().is_like_clang() {
+ if target.os == WINDOWS
+ && (target.arch == AARCH64 || target.arch == ARM)
+ && !c.get_compiler().is_like_clang()
+ {
  let _ = c.compiler("clang");
  }
 
@@ -619,7 +651,7 @@ fn configure_cc(c: &mut cc::Build, target: &Target, include_dir: &Path) {
  }
 }
 
-/// Assembles the assemply language source `file` into the object file
+/// Assembles the assembly language source `file` into the object file
 /// `out_file`.
 fn cc_asm(b: &cc::Build, file: &Path, out_file: &Path) -> Command {
  let cc = b.get_compiler();

crypto/perlasm/arm-xlate.pl

@@ -31,7 +31,7 @@
 };
 my $hidden = sub {
  if ($flavour =~ /ios/) { ".private_extern\t".join(',',@_); }
- elsif ($flavour =~ /win64/) { ""; }
+ elsif ($flavour =~ /win/) { ""; }
  else { ".hidden\t".join(',',@_); }
 };
 my $comm = sub {

src/aead/aes.rs

@@ -146,7 +146,7 @@ impl Key {
  match detect_implementation(cpu_features) {
  #[cfg(any(
  target_arch = "aarch64",
- target_arch = "arm",
+ all(target_arch = "arm", not(target_os = "windows")),
  target_arch = "x86_64",
  target_arch = "x86"
  ))]
@@ -181,7 +181,7 @@ impl Key {
  match detect_implementation(self.cpu_features) {
  #[cfg(any(
  target_arch = "aarch64",
- target_arch = "arm",
+ all(target_arch = "arm", not(target_os = "windows")),
  target_arch = "x86_64",
  target_arch = "x86"
  ))]
@@ -220,7 +220,7 @@ impl Key {
  match detect_implementation(self.cpu_features) {
  #[cfg(any(
  target_arch = "aarch64",
- target_arch = "arm",
+ all(target_arch = "arm", not(target_os = "windows")),
  target_arch = "x86_64",
  target_arch = "x86"
  ))]
@@ -370,7 +370,7 @@ impl Iv {
 pub enum Implementation {
  #[cfg(any(
  target_arch = "aarch64",
- target_arch = "arm",
+ all(target_arch = "arm", not(target_os = "windows")),
  target_arch = "x86_64",
  target_arch = "x86"
  ))]
@@ -401,7 +401,7 @@ fn detect_implementation(cpu_features: cpu::Features) -> Implementation {
 
  #[cfg(any(
  target_arch = "aarch64",
- target_arch = "arm",
+ all(target_arch = "arm", not(target_os = "windows")),
  target_arch = "x86_64",
  target_arch = "x86"
  ))]

src/aead/gcm.rs

@@ -53,7 +53,7 @@ impl Key {
 
  #[cfg(any(
  target_arch = "aarch64",
- target_arch = "arm",
+ all(target_arch = "arm", not(target_os = "windows")),
  target_arch = "x86_64",
  target_arch = "x86"
  ))]
@@ -154,7 +154,7 @@ impl Context {
 
  #[cfg(any(
  target_arch = "aarch64",
- target_arch = "arm",
+ all(target_arch = "arm", not(target_os = "windows")),
  target_arch = "x86_64",
  target_arch = "x86"
  ))]
@@ -206,7 +206,7 @@ impl Context {
  match detect_implementation(self.cpu_features) {
  #[cfg(any(
  target_arch = "aarch64",
- target_arch = "arm",
+ all(target_arch = "arm", not(target_os = "windows")),
  target_arch = "x86_64",
  target_arch = "x86"
  ))]
@@ -298,7 +298,7 @@ struct ContextInner {
 enum Implementation {
  #[cfg(any(
  target_arch = "aarch64",
- target_arch = "arm",
+ all(target_arch = "arm", not(target_os = "windows")),
  target_arch = "x86_64",
  target_arch = "x86"
  ))]
@@ -324,7 +324,7 @@ fn detect_implementation(cpu_features: cpu::Features) -> Implementation {
 
  #[cfg(any(
  target_arch = "aarch64",
- target_arch = "arm",
+ all(target_arch = "arm", not(target_os = "windows")),
  target_arch = "x86_64",
  target_arch = "x86"
  ))]

src/aead/poly1305.rs

@@ -60,7 +60,7 @@ macro_rules! dispatch {
  ( $( $a:expr ),+ ) ) => {
  match () {
  // Apple's 32-bit ARM ABI is incompatible with the assembly code.
- #[cfg(all(target_arch = "arm", not(target_vendor = "apple")))]
+ #[cfg(all(target_arch = "arm", not(any(target_vendor = "apple", target_os = "windows"))))]
  () if cpu::arm::NEON.available($features) => {
  prefixed_extern! {
  fn $neon_f( $( $p : $t ),+ );

src/cpu/arm.rs

@@ -122,6 +122,24 @@ fn detect_features() -> u32 {
  features
 }
 
+#[cfg(all(target_os = "windows", target_arch = "arm"))]
+fn detect_features() -> u32 {
+ extern "C" {
+ fn IsProcessorFeaturePresent(ProcessorFeature: u32) -> i32;
+ }
+ const PF_ARM_VFP_32_REGISTERS_AVAILABLE: u32 = 18;
+
+ let mut features = 0;
+
+ let result = unsafe { IsProcessorFeaturePresent(PF_ARM_VFP_32_REGISTERS_AVAILABLE) };
+
+ if result != 0 {
+ features |= NEON.mask;
+ }
+
+ features
+}
+
 #[cfg(all(target_os = "windows", target_arch = "aarch64"))]
 fn detect_features() -> u32 {
  // We do not need to check for the presence of NEON, as Armv8-A always has it

src/ec/curve25519/x25519.rs

@@ -63,7 +63,10 @@ fn x25519_public_from_private(
  let private_key: &[u8; SCALAR_LEN] = private_key.bytes_less_safe().try_into()?;
  let private_key = ops::MaskedScalar::from_bytes_masked(*private_key);
 
- #[cfg(all(not(target_os = "ios"), target_arch = "arm"))]
+ #[cfg(all(
+ not(any(target_os = "ios", target_os = "windows")),
+ target_arch = "arm"
+ ))]
  {
  if cpu::arm::NEON.available(cpu_features) {
  static MONTGOMERY_BASE_POINT: [u8; 32] = [
@@ -109,7 +112,10 @@ fn x25519_ecdh(
  point: &ops::EncodedPoint,
  #[allow(unused_variables)] cpu_features: cpu::Features,
  ) {
- #[cfg(all(not(target_os = "ios"), target_arch = "arm"))]
+ #[cfg(all(
+ not(any(target_os = "ios", target_os = "windows")),
+ target_arch = "arm"
+ ))]
  {
  if cpu::arm::NEON.available(cpu_features) {
  return x25519_neon(out, scalar, point);
@@ -158,7 +164,10 @@ fn x25519_ecdh(
  Ok(())
 }
 
-#[cfg(all(not(target_os = "ios"), target_arch = "arm"))]
+#[cfg(all(
+ not(any(target_os = "ios", target_os = "windows")),
+ target_arch = "arm"
+))]
 fn x25519_neon(out: &mut ops::EncodedPoint, scalar: &ops::MaskedScalar, point: &ops::EncodedPoint) {
  prefixed_extern! {
  fn x25519_NEON(